General relativity includes a dynamical spacetime, so it is difficult to see how to identify the conserved energy and momentum. Noether's theorem allows these quantities to be determined from a Lagrangian with translation invariance, but general covariance makes translation invariance into something of a gauge symmetry. The energy and momentum derived within general relativity by Noether's presecriptions do not make a real tensor for this reason. Einstein argued that this is true for fundamental reasons, because the gravitational field could be made to vanish by a choice of coordinates. He maintained that the non-covariant energy momentum pseudotensor was in fact the best description of the energy momentum distribution in a gravitational field. This approach has been echoed by Lev Landau and Evgeny Lifshitz, and others, and has become standard. The use of non-covariant objects like pseudotensors was heavily criticized in 1917 by Erwin Schrodinger and others. 

Who's theory did not have a more precise symmetry for conserved energy and momentum?


Charlie Y. Reader is a 35-year-old theatrical agent in New York , living a seemingly idyllic life as a bachelor . Numerous women ( among them Poppy , Helen , and Jessica come and go , cleaning and cooking for him . Charlie 's best friend since kindergarten , Joe McCall , who has a wife named Ethel and children in Indianapolis , comes to New York for a stay at Charlie 's apartment , claiming that the excitement is gone from his 11-year marriage and that he wants to leave his wife . Joe envies and is amazed by Charlie 's parade of girlfriends , while Charlie professes admiration for Joe 's married life and family . At an audition , Charlie meets singer-actress Julie Gillis . She has her life planned to a tight schedule , determined to marry and retire from performing to a life of child-rearing by 22 . Although at first she wards off Charlie 's advances , she comes to see him as the ideal man for her plans . Julie demands that Charlie stop seeing other women . Charlie balks , but he begins to fall in love with her . Joe starts keeping company with Sylvia Crewes , a sophisticated classical musician and a typically neglected lover of Charlie 's . Sylvia is approaching 33 and desires marriage as much as the younger Julie does . One day , annoyed by Julie and possibly jealous of Joe 's attentions , Charlie blurts out a proposal of marriage to Sylvia . She is thrilled , only to discover the morning after their engagement party that he has proposed to Julie as well . Joe confesses his love to Sylvia and asks her to marry him . 

What interest do Julie and Sylvia have in common?


A stranger in town meets pretty young Susan Martinez De La Cruz and accompanies her to a barbecue , where wealthy Jason Carberry is saying a few words for the recently departed Robin Randall , a citizen who got shot .  Jason objects to the stranger's presence , being Susan's guardian and protective of her .  He challenges him to a shootout , but the stranger pulls his pistol before Jason's can even clear the holster .  Calaveras Kate , a saloon singer who's in love with Jason , is relieved when the stranger declines to pull the trigger .  Rafael Moreno suddenly rides into town and picks a fight with the stranger .  Their brawl continues until the arrival of Judge Wallace Wintrop and his niece , Sheila , who have come to town from back East and deplore all this random violence out West .  The stranger is recognized as Reb Randall , the dead man's brother .  He is looking for the killer , who could be Rafael , or could be Jason , or could even be Billy Buckett , the coward of the county .  The women hold their breath to see if the men they love will survive . 


How does Jason react to the stranger's presence and what is his name?